And “100% busy” is the wrong criterion – if you want your system to be performant.
Cheers, Martin From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> on behalf of Peter Relson <rel...@us.ibm.com> Date: Tuesday, 5 September 2023 at 13:13 To: IBM-MAIN@LISTSERV.UA.EDU <IBM-MAIN@LISTSERV.UA.EDU> Subject: [EXTERNAL] Re: Switching between SMT-1 and SMT-2 <snip> The current situation sounds like SMT-2 should only be used if you a) have a single zIIP or b) are running your zIIPs consistently 100% busy and for b) you need to turn it off when the workload reduces? <snip> I don't think that that is a correct conclusion. It is far more complicated than thinking that this is simply about one LPAR. It depends what your logical vs physical configuration is. It depends what resources your other LPARs need. And a lot more. And it is expected that zIIPs are not run "consistently 100% busy". That would not be an appropriate usage of zIIPs. Peter Relson z/OS Core Technology Design ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN Unless otherwise stated above: IBM United Kingdom Limited Registered in England and Wales with number 741598 Registered office: PO Box 41, North Harbour, Portsmouth, Hants. PO6 3AU ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
